178 
PALAEONTOLOGY OF NEW YORK. 
tions; and they are of the same geological age in the two countries. In 
very numerous examples these fossils are striated transversely or longitudi¬ 
nally, and not unfrequently the two sets of striae are visible on the same speci¬ 
men. These are apparently only varieties of form and condition of the Styliola 
fissurella. 
Styliola fissurella. 
PLATE XXXI A, FIGS. 1-30. 
Tentaculites fissurella, Hall. Geol. of N. Y. Surv. Fourth Geolog. Dist., p. ISO, figs. 9 and 10, and p. 222, 
fig. 4. 1843. 
Not Tentaculites fissurella, Hall. Illustrations of Devonian Fossils: Pteropoda, pi. 25, figs. 12-14.* 1876._ 
Form an extremely slender, elongate cone, like the point of a small needle. 
Apical portion of the tube solid. Apex extremely minute, often bulbiform, 
and very gradually enlarging to the mouth. 
Surface often smooth and without any visible ornamentation, so far as can be 
determined; or with fine striae of growth, which are unequally developed 
on different parts of the shell; and also with fine longitudinal striae, which 
may be present with or without transverse striae. Usual length from one 
to two, sometimes two and a half, and rarely five millimetres. 
This species occurs in the Marcellus shale and lower part of the Hamilton 
group, associated with Tentaculites gracilistriatus, and it is quite possible that some 
of the larger specimens, noticed in the mass of individuals, may be casts of the 
interior of that fossil, which do not show the marks of annulations, and in such 
conditions the smaller forms may not always be readily distinguishable from 
the smooth apices of the Tentaculites. These two species together often com¬ 
pose almost entire layers of the rock. 
In the soft calcareous shales, the Styliola retains nearly its full form; while 
in the finely laminated slates it is always compressed, except the solid apex, 
showing a sharply depressed line of fracture for nearly its entire length; and 
* The specimens figured in the “Illustrations of Devonian Fossils” were from slabs containing both 
he Styliola and Tentaculites gracilistriatus, and the erroneous reference escaped the author’s notice. 
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